82 lines
3.9 KiB
Plaintext
82 lines
3.9 KiB
Plaintext
create user foo@localhost;
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grant ALL on *.* to foo@localhost;
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truncate table performance_schema.events_transactions_current;
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# Connection 1
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select connection_id() into @conid;
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start transaction;
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# Default connection
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====================================================================
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Testing index for columns THREAD_ID, EVENT_ID
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====================================================================
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############ Explain for Query ####################################
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explain select END_EVENT_ID
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from performance_schema.events_transactions_current
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where THREAD_ID = "impossible";
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id select_type table partitions type possible_keys key key_len ref rows filtered Extra
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1 SIMPLE events_transactions_current NULL ref PRIMARY PRIMARY 8 const # 100.00 Using where
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############ Explain for Query ####################################
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explain select END_EVENT_ID
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from performance_schema.events_transactions_current
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where THREAD_ID > "impossible";
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id select_type table partitions type possible_keys key key_len ref rows filtered Extra
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1 SIMPLE events_transactions_current NULL ALL PRIMARY NULL NULL NULL # 33.33 Using where
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############ Explain for Query ####################################
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explain select END_EVENT_ID
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from performance_schema.events_transactions_current
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where THREAD_ID < "2";
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id select_type table partitions type possible_keys key key_len ref rows filtered Extra
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1 SIMPLE events_transactions_current NULL ALL PRIMARY NULL NULL NULL # 33.33 Using where
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############ Explain for Query ####################################
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explain select END_EVENT_ID
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from performance_schema.events_transactions_current
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where THREAD_ID = @tid;
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id select_type table partitions type possible_keys key key_len ref rows filtered Extra
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1 SIMPLE events_transactions_current NULL ref PRIMARY PRIMARY 8 const # 100.00 Using where
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############ Explain for Query ####################################
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explain select END_EVENT_ID
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from performance_schema.events_transactions_current
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where THREAD_ID = "impossible"
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and EVENT_ID = "impossible";
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id select_type table partitions type possible_keys key key_len ref rows filtered Extra
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1 SIMPLE NULL NULL NULL NULL NULL NULL NULL # NULL no matching row in const table
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############ Explain for Query ####################################
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explain select END_EVENT_ID
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from performance_schema.events_transactions_current
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where THREAD_ID = @tid
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and EVENT_ID = "impossible";
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id select_type table partitions type possible_keys key key_len ref rows filtered Extra
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1 SIMPLE NULL NULL NULL NULL NULL NULL NULL # NULL no matching row in const table
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############ Explain for Query ####################################
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explain select END_EVENT_ID
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from performance_schema.events_transactions_current
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where THREAD_ID = @tid
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and EVENT_ID > "impossible";
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id select_type table partitions type possible_keys key key_len ref rows filtered Extra
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1 SIMPLE events_transactions_current NULL ref PRIMARY PRIMARY 8 const # 33.33 Using where
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############ Explain for Query ####################################
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explain select END_EVENT_ID
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from performance_schema.events_transactions_current
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where THREAD_ID = @tid
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and EVENT_ID < "2";
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id select_type table partitions type possible_keys key key_len ref rows filtered Extra
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1 SIMPLE events_transactions_current NULL ref PRIMARY PRIMARY 8 const # 33.33 Using where
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############ Explain for Query ####################################
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explain select END_EVENT_ID
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from performance_schema.events_transactions_current
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where THREAD_ID = @tid
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and EVENT_ID = @eid;
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id select_type table partitions type possible_keys key key_len ref rows filtered Extra
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1 SIMPLE events_transactions_current NULL const PRIMARY PRIMARY 16 const,const # 100.00 NULL
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############# Explain End #########################################
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flush status;
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select END_EVENT_ID
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from performance_schema.events_transactions_current
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where THREAD_ID = @tid
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and EVENT_ID = @eid;
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END_EVENT_ID
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#
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OK: handler_read_key incremented
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commit;
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drop user foo@localhost;
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